Nikita Belykh, a Kirov regional governor and Kremlin critic who was detained on bribery charges this week, has started a hunger strike, his lawyer announced on June 29.

"Belykh officially notified the [Lefortovo] prison administration that he is beginning a hunger strike to protest his indictment and because he has not been allowed to see his second lawyer," Olga Mikhailova, said attorney Vadim Prokhorov.

Belykh categorically denies taking any bribes, he said, adding that the governor "really doesn't look healthy and his condition is highly unstable."

Belykh has been known in the past as a Kremlin critic and was formerly a leader of the liberal opposition party, Union of Rightist Forces, along with slain politician Boris Nemtsov.

The Russian Investigative Committee claims that Belykh admitted to taking a 400,000 euro ($444,000) bribe at a Moscow restaurant where he was arrested on June 24.

"I stress that Nikita Belykh has maintained his total innocence," Prokhorov said.

Belykh has not been allowed visits by Mikhailova or his wife and brother, he said.